6.5-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Justin Stitt <[email protected]>

[ Upstream commit 4b2fd81f2af7147e844ecec0c5c07a16bca6b86e ]

`strncpy` is deprecated for use on NUL-terminated destination strings [1].

A suitable replacement is `strscpy` [2] due to the fact that it
guarantees NUL-termination on its destination buffer argument which is
_not_ the case for `strncpy`!

Also remove extraneous if-statement as it can never be entered. The
return value from `strncpy` is it's first argument. In this case,
`...dyndbg_cmd` is an array:
|       char dyndbg_cmd[VPU_DYNDBG_CMD_MAX_LEN];
             ^^^^^^^^^^
This can never be NULL which means `strncpy`'s return value cannot be
NULL here. Just use `strscpy` which is more robust and results in
simpler and less ambiguous code.

Moreover, remove needless `... - 1` as `strscpy`'s implementation
ensures NUL-termination and we do not need to carefully dance around
ending boundaries with a "- 1" anymore.

Fixes: 5d7422cfb498 ("accel/ivpu: Add IPC driver and JSM messages")
Link: 
www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
 [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
Reviewed-by: Stanislaw Gruszka <[email protected]>
Signed-off-by: Stanislaw Gruszka <[email protected]>
Link: 
https://patchwork.freedesktop.org/patch/msgid/20230824-strncpy-drivers-accel-ivpu-ivpu_jsm_msg-c-v1-1-12d9b52d2...@google.com
Signed-off-by: Sasha Levin <[email protected]>
---
 drivers/accel/ivpu/ivpu_jsm_msg.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/accel/ivpu/ivpu_jsm_msg.c 
b/drivers/accel/ivpu/ivpu_jsm_msg.c
index 831bfd2b2d39d..bdddef2c59eec 100644
--- a/drivers/accel/ivpu/ivpu_jsm_msg.c
+++ b/drivers/accel/ivpu/ivpu_jsm_msg.c
@@ -118,8 +118,7 @@ int ivpu_jsm_dyndbg_control(struct ivpu_device *vdev, char 
*command, size_t size
        struct vpu_jsm_msg resp;
        int ret;
 
-       if (!strncpy(req.payload.dyndbg_control.dyndbg_cmd, command, 
VPU_DYNDBG_CMD_MAX_LEN - 1))
-               return -ENOMEM;
+       strscpy(req.payload.dyndbg_control.dyndbg_cmd, command, 
VPU_DYNDBG_CMD_MAX_LEN);
 
        ret = ivpu_ipc_send_receive(vdev, &req, VPU_JSM_MSG_DYNDBG_CONTROL_RSP, 
&resp,
                                    VPU_IPC_CHAN_ASYNC_CMD, vdev->timeout.jsm);
-- 
2.40.1



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